Question: when did Eric Clapton become a member of John Mayall & the Bluabreakers?
Paraphrase: What did did Eric Clapton beome a member of John Mayall & the Bluabreakers?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q48187 p:P463 ?s . ?s ps:P463 wd:Q886072 . ?s pq:P582 ?value}